package com.wstro.util;

import javax.imageio.ImageIO;
import javax.imageio.ImageReader;
import javax.imageio.stream.ImageInputStream;
import java.awt.image.BufferedImage;
import java.io.*;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Map.Entry;

/**
 * 文件帮助类
 *
 * @author Joey
 * @Email 2434387555@qq.com
 */
public class FileTypeHelp {
    public final static Map<String, String> FILE_TYPE_MAP = new HashMap<String, String>();

    private FileTypeHelp() {
    }

    static {
        getAllFileType(); // 初始化文件类型信息
    }

    /**
     * Created on 2010-7-1
     * <p>
     * Discription:[getAllFileType,常见文件头信息]
     * </p>
     *
     * @author:[shixing_11@sina.com]
     */
    private static void getAllFileType() {
        FILE_TYPE_MAP.put("jpg", "FFD8FF"); // JPEG (jpg)
        FILE_TYPE_MAP.put("png", "89504E47"); // PNG (png)
        FILE_TYPE_MAP.put("gif", "47494638"); // GIF (gif)
        FILE_TYPE_MAP.put("tif", "49492A00"); // TIFF (tif)
        FILE_TYPE_MAP.put("bmp", "424D"); // Windows Bitmap (bmp)
        FILE_TYPE_MAP.put("dwg", "41433130"); // CAD (dwg)
        FILE_TYPE_MAP.put("html", "68746D6C3E"); // HTML (html)
        FILE_TYPE_MAP.put("rtf", "7B5C727466"); // Rich Text Format (rtf)
        FILE_TYPE_MAP.put("xml", "3C3F786D6C");
        FILE_TYPE_MAP.put("zip", "504B0304");
        FILE_TYPE_MAP.put("rar", "52617221");
        FILE_TYPE_MAP.put("psd", "38425053"); // Photoshop (psd)
        FILE_TYPE_MAP.put("eml", "44656C69766572792D646174653A"); // Email
        // [thorough
        // only]
        // (eml)
        FILE_TYPE_MAP.put("dbx", "CFAD12FEC5FD746F"); // Outlook Express (dbx)
        FILE_TYPE_MAP.put("pst", "2142444E"); // Outlook (pst)
        FILE_TYPE_MAP.put("xls", "D0CF11E0"); // MS Word
        FILE_TYPE_MAP.put("doc", "D0CF11E0"); // MS Excel 注意：word 和 excel的文件头一样
        FILE_TYPE_MAP.put("mdb", "5374616E64617264204A"); // MS Access (mdb)
        FILE_TYPE_MAP.put("wpd", "FF575043"); // WordPerfect (wpd)
        FILE_TYPE_MAP.put("eps", "252150532D41646F6265");
        FILE_TYPE_MAP.put("ps", "252150532D41646F6265");
        FILE_TYPE_MAP.put("pdf", "255044462D312E"); // Adobe Acrobat (pdf)
        FILE_TYPE_MAP.put("qdf", "AC9EBD8F"); // Quicken (qdf)
        FILE_TYPE_MAP.put("pwl", "E3828596"); // Windows Password (pwl)
        FILE_TYPE_MAP.put("wav", "57415645"); // Wave (wav)
        FILE_TYPE_MAP.put("avi", "41564920");
        FILE_TYPE_MAP.put("ram", "2E7261FD"); // Real Audio (ram)
        FILE_TYPE_MAP.put("rm", "2E524D46"); // Real Media (rm)
        FILE_TYPE_MAP.put("mpg", "000001BA"); //
        FILE_TYPE_MAP.put("mov", "6D6F6F76"); // Quicktime (mov)
        FILE_TYPE_MAP.put("asf", "3026B2758E66CF11"); // Windows Media (asf)
        FILE_TYPE_MAP.put("mid", "4D546864"); // MIDI (mid)
    }

    public static void main(String[] args) throws Exception {
        File f = new File("c://aaa.gif");
        if (f.exists()) {
            String filetype1 = getImageFileType(f);
            System.out.println(filetype1);
            String filetype2 = getFileByFile(f);
            System.out.println(filetype2);
        }
    }

    /**
     * Created on 2010-7-1
     * <p>
     * Discription:[getImageFileType,获取图片文件实际类型,若不是图片则返回null]
     * </p>
     *
     * @param File
     * @return fileType
     * @author:[shixing_11@sina.com]
     */
    public final static String getImageFileType(File f) {
        if (isImage(f)) {
            try {
                ImageInputStream iis = ImageIO.createImageInputStream(f);
                Iterator<ImageReader> iter = ImageIO.getImageReaders(iis);
                if (!iter.hasNext()) {
                    return null;
                }
                ImageReader reader = iter.next();
                iis.close();
                return reader.getFormatName();
            } catch (IOException e) {
                return null;
            } catch (Exception e) {
                return null;
            }
        }
        return null;
    }

    /**
     * Created on 2010-7-1
     * <p>
     * Discription:[getFileByFile,获取文件类型,包括图片,若格式不是已配置的,则返回null]
     * </p>
     *
     * @param file
     * @return fileType
     * @author:[shixing_11@sina.com]
     */
    public final static String getFileByFile(File file) {
        String filetype = null;
        byte[] b = new byte[50];
        try {
            InputStream is = new FileInputStream(file);
            is.read(b);
            filetype = getFileTypeByStream(b);
            is.close();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return filetype;
    }

    /**
     * Created on 2010-7-1
     * <p>
     * Discription:[getFileTypeByStream]
     * </p>
     *
     * @param b
     * @return fileType
     * @author:[shixing_11@sina.com]
     */
    public final static String getFileTypeByStream(byte[] b) {
        String filetypeHex = String.valueOf(getFileHexString(b));
        Iterator<Entry<String, String>> entryiterator = FILE_TYPE_MAP.entrySet().iterator();
        while (entryiterator.hasNext()) {
            Entry<String, String> entry = entryiterator.next();
            String fileTypeHexValue = entry.getValue();
            if (filetypeHex.toUpperCase().startsWith(fileTypeHexValue)) {
                return entry.getKey();
            }
        }
        return null;
    }

    /**
     * Created on 2010-7-2
     * <p>
     * Discription:[isImage,判断文件是否为图片]
     * </p>
     *
     * @param file
     * @return true 是 | false 否
     * @author:[shixing_11@sina.com]
     */
    public static final boolean isImage(File file) {
        boolean flag = false;
        try {
            BufferedImage bufreader = ImageIO.read(file);
            int width = bufreader.getWidth();
            int height = bufreader.getHeight();
            if (width == 0 || height == 0) {
                flag = false;
            } else {
                flag = true;
            }
        } catch (IOException e) {
            flag = false;
        } catch (Exception e) {
            flag = false;
        }
        return flag;
    }

    /**
     * Created on 2010-7-1
     * <p>
     * Discription:[getFileHexString]
     * </p>
     *
     * @param b
     * @return fileTypeHex
     * @author:[shixing_11@sina.com]
     */
    public final static String getFileHexString(byte[] b) {
        StringBuilder stringBuilder = new StringBuilder();
        if (b == null || b.length <= 0) {
            return null;
        }
        for (int i = 0; i < b.length; i++) {
            int v = b[i] & 0xFF;
            String hv = Integer.toHexString(v);
            if (hv.length() < 2) {
                stringBuilder.append(0);
            }
            stringBuilder.append(hv);
        }
        return stringBuilder.toString();
    }
}